Intradiscal Glucocorticoid Injection in Discogenic Back Pain and Influence on Modic Changes: A Systematic Review and Meta-analysis of RCTs

Background: The benefit of intradiscal glucocorticoid injection (IGI) for discogenic low back pain (LBP) remains controversial. Objectives: The objective of this study was to systematically assess and meta-analyze the efficacy of IGI compared with these control groups. Study Design: Systematic review and meta-analysis. Methods: A comprehensive literature search was performed screening PubMed and Embase through May 2022. Only randomized controlled trials (RCTs) comparing IGI to control groups in adult patients with discogenic lumbar back pain were included. A random effects model was used to pool mean differences of pain intensity (visual analaog scale [VAS] 0-100), and physical function assessed with the Oswestry Disability Index (ODI). Subgroup analyses were stratified by Modic magnetic resonance imaging findings. Results: Seven studies met inclusion criteria with a total of 626 patients. The short-term (< 3 months) follow-up showed a significant pooled mean difference in both pain intensity (-20.1; 95% CI,-25.5 to-14.7) and physical function (-9.9; 95% CI,-16.1 to-3.6). In the intermediate-term follow-up (3 to < 6 months), only physical function remained significantly better in the glucocorticoid group (-13.1; 95% CI,-22.3 to-3.9). There was no clinically meaningful or significant difference in pain scores and physical function at the long-term (≥ 6 months) follow-up. A subgroup analysis did not demonstrate an effect of Modic (type I) changes on the efficacy of IGI. Limitations: A limited number of studies was available and consequently publication bias could not be evaluated using a funnel plot. Statistical heterogeneity was detected among the included studies. Conclusion: We conclude that IGI reduces discogenic LBP intensity and improves physical function effectively at short-term follow-up, and continues to improve physical function at intermediate-term. However, 6 months posttreatment, outcomes are similar in comparison to the control groups. The type of Modic change does not appear to be related with the response to IGI.